Spinning tool



Aug. 21, 1945. L. w. MICHAEL SPINNING TOOL Filed May 5, 1943 INVENTOR Z az rence 11/. fiz'cfmel.

ATTORNEY Patented Aug; 21, 1945 2,383,339 V f SPINNING 'rooL Lawrence W. Michael, Lima, 0hio ApplicationMay 5, 194s,seria1N'o. 485,789 I 5 Claims. (Cl. 218-14 This invention relates to a spinning tool for forming metallic eyelets orygrcmmets, and more particualrly to an improved tool adapted to form the. end of a grommet to conform toa surface having anirregularcontour. a i

. The use of metallic rings or grommets com prising a short metallic tube, the ends of which are bent outwardlya'nd over to fasten it in place as a liner for an openingin a plate-like'structure, is well known. However, toolsfor form ing the grommet have been founddefective where the grommet is to be used as a liner for an opening in a plate having an irregular contour, such as on a curved plate. In such cases, the bent-over end or lip of the grommet engages only with the high a points on the plate and is spaced fromthe low'points in= such plate. Con sequently, the grommets "frequently are not securely fastened. to the structure in which the opening is formed where such structure has a curvedsurface or a surface of an otherwise irregular contour. it a One of theprincipal objectsoi this invention is toprovide .an improved tool which is capable of shaping the end of the grommet to conform with the contour of mounted. i l

A further object of the invention is to provide a spinning tool for forming (grommets which has a working surface-movable in an annular path to formthe endof a grommet, and in which such working surface is carried by a part 'movable back and forth -parallel to the axis of ro tation of the tool, sothat the grommet .endmay a surface having an on which the'grommet is to be mounted so that thegrommet end will be firmly "engaged with such surface entirely around its periphery.

tion will be apparent from the following description and accompanying drawing, in which:

Figure 1 is alongitudinal sectional View 'of a] spinning tool constructed in accordance with the principles of this invention, the section being taken along the line I- -I indicated in Fig. 3;

Fig. 2 is a side elevational view of a matrix die part for cooperation with the tool shown in Fig. 1, a part of Fig. 2 being shown in'section; 55 in Fig. 2, the tool 2 is rotated and lowered until the surface in which it is i Fig. 3 is a sectional View taken on the line III--III ofFig. 1; and a i i Fig. 4 is aview. similarytolFig. 2 illustrating the .final. step in securing a grommet in position as a liner for an opening formed inuan articlehavinga curved surface. l a Referring to the drawing, the numeral l designates a. tool holder adapted to be secured to a drill pess. of similar conventional construction.

by which it may be rotated while being moved in an axial direction. .lTheholder I comprises a prises separate sector-shaped sections 5 which whenmounted. together asshown form a cylindrical tool 4. Each of the sections 5 is provided with a ledge 6 adapted to. engage with a ring 'I which is secured to the body 2 by fastening ele ments 8, and has a portion thereof projecting radially inwardly from the mouth of the opening 3.. A spring 9 isprovided for each section 5 to bias such sections to a limited position in the holder 2 with the ledge 6 in engagement with thewring 1. By this construction, the sections 5 aretmovable independently of each other in an axialtdirection within the holder 2 against the bias of the springs 9 for a purpose to be described} t Q Projecting outwardly from the ledge 6 and toolholder 2 each of the sections 5 is so formed that they .collectively'provide a cylindrical end portion ID on the tool 4 which is receivablein an opening .ll formed in a matrix. die part l2.

The diameters of the cylindrical end opening l0 and opening H are made. to conform to the inner diameterof the grommet to be formed. The opening H is enlarged as at ls to provide .a

ledge for holding a metallic tube in position one of its end portions is formed. A member l4 having an opening therein aligned with the open ing H and a-surface conforming to the surface on which the grommet is. to be finally secured l is shown in position on. the matrix die part II. Other objects and advantages of this jinven- A metallic tube 5 is then placed in position with its lower edge resting on the surface provided by the enlarged opening 13 as shown in Fig. 2.

Each of the sections 5'is provided with a cupshaped recess. [6 so that they, collectively form the cup-shaped recess l6 engages with the top of the tube [5. Further downward movement of the tool holder 2 will cause the sections to move upwardly and compress the springs 9. A spinning action will then be had which will bend the end of the tube outwardly to form the grommet lip portion l1. As the tool is rotated, each of the sections 5 will move axially in a path determined by the contour of the upper surface on the member M. The working surfaces IE on each of the segmental sections 5 engage only with a portion of the grommet l5, and since they are movable independently of each otherare effective to form the grommet end as shown in Fig. 2.

A subsequent operation with the tool 2. is effective to form the other end of the grommet l5 and to fixedly secure it in position. In Fig. 4, there is shown an article l8 having an opening I9 formed therein. A matrix 20 having an open-.

ing 2| formed therein similar to the opening I l is provided for the final operation. The grommet I5 with its end I1. shaped to conform with the curved surface 22 of the article I8 is mounted in position with the end I! positionedon the matrix 20 as shown in Fig. 2. The tool portion 4, as shown in dotted lines in Fig. 4, may then be rotated and lowered to form the grommet end 23. In this manner, the grommet ends I1 and 23 are firmly engaged with both of the surfaces defining the opening I 9, and such engagement is had uniformly around the entire periphery of the opening l9.

From the foregoing, it will be apparent that there is provided a spinning tool which is effective to form grommet ends to conform with the surface contour of the article mounting the same. By forming the tool of separate sections, each of which is spring biased into engagement with the work, there is provided a plurality of metal working surfaces respectively movable in an annular path to perform spinning operations while moving axially in accordance with the contour of the surface on which the metal is being worked. The

springs are effective to move the tool section downwardly to force the metal being worked ing in which the grommet is mounted.

Since certain changes may be made in the above construction and different embodiments of the invention may be mad without departing from the scope thereof, it is intended that all matter contained in the above description or shownin the accompanying drawing shall be interpreted as illustrative and not in a limiting sense.

I claim as my invention:

1. A spinning tool for shaping-the end of a grommet to conform with a surface of irregular contour comprising a rotatable holder, a grommet shaping die comprised of a plurality of separate cooperating sections of sector-shaped cross-section arranged so as to form a substantially continuous cylindrical die surface, and

means mounting said sections in said holder for movement, independently of each other, in an axial direction with respect to said holder.

2. A spinning tool for shaping the end of a grommet to conform with a surface of irregular contour comprising a rotatable holder, a grommet shaping die comprised of a plurality of separate cooperating sections, means mounting said sections in said holder for movement, independently of each other, in an axialdirection with respect to said holder, and a separate spring for each of said sections for biasing said sections outwardly to a limited position in said holder, each of said sections being movable inwardly against its bias to follow the contour of the surface on which the grommet end is being formed.

3. A grommet forming apparatus, comprising a cylindrical shaping tool having a cylindrical end portion and a cup-shaped annular ledge positioned inwardly of said end portion for shaping the end of a grommet, said end portion having a diameter conforming to the inner diameter of the grommet to be shaped, a rotatable holder for said tool, said tool'comprising a pluralityof separate sector-shaped sections, and means mounting said sections in said holder for movement, independently of each other, in an axial direction with respect to said holder, such axial movement being had upon rotation of said holder and. the shaping of the grommet end uniformly about an opening in a matrix by said cup-shaped ledge.

4. A grommet forming apparatus, comprising a cylindrical shaping tool having a cylindrical end portion and a cup-shaped annular ledge positioned inwardly of said end portion for shaping the end of a grommet, said end portion having a diameter conforming to the inner diameter of the. grommet to be shaped, a rotatable holder for said tool, said tool comprising a plurality of separate sector-shaped sections, means mounting said sections in said holder for movement, independently of each other, in an axial direction with respect to said holder, and individual springs for biasing each of said sections outwardly to a limited position in said holder, said sections being movable inwardly against the bias :of said springs upon rotation of said holder and the l:

shaping of the grommet end by said cup -shaped ledge.

5. Ina tool of the character described, a hold-' er comprising a body portion having a cylindrical recess disposed so as to form an opening at one end of said'portion, a working tool comprising a plurality of sector-shaped sections cooper-' ating together to form a cylindrical device receivable in said recess, said sections being formed to provide an annular ledge intermediate the ends of said device, a retaining ring secured to said body portion and extending radially inwardly from the opening of said recess for engagement with said ledge to prevent movement of said sections out of said opening, each of said LAWRENCE W. MICHAEL, 

